Prostate cancer is the most prevalent cancer in men. Diagnosis is based on a tissue biopsy, microscopic examination of a small section of the prostate. When the biopsy contains cancerous cells the therapeutic options generally include radio- and chemotherapies, hormone treatments as well as surgical removal of the prostate gland. It is well known that these treatments are frequently devastating for the patient and notwithstanding these therapies mortality from prostate cancer is high.
There is an urgent need for agents that prevent the advancement of prostate cancer. Indeed, of the approximately one million prostate biopsies performed in this country every year, by far the majority are negative. Yet these men suffer a range of symptoms associated with elevated PSA levels and benign prostatic hyperplasia affecting urinary and sexual function. These large groups of men with BPH (Benign Prostatic Hyperplasia) or elevated PSA, or with PIN (prostatic intraepithelial neoplasia), but with negative biopsies, are precancerous: they are at high risk of developing an aggressive prostate cancer and there have been no effective preventive treatments. Agents that forestall or significantly delay the onset of cancer in this population have remarkable therapeutic value.
Another large population of men is diagnosed with prostate cancer, but their biopsies reveal a low-grade form of the disease. This group is in the well-known ‘watchful waiting’ or ‘active surveillance’ category and when the rate of increase in their PSA levels is relatively rapid they are subject to the therapeutic interventions cited above. These large groups of men—those in watchful waiting and those with shorter PSA doubling times need agents that subdue their cancers, slow the rate of PSA increase, and prevent the progression of their cancers to a higher grade and more aggressive form. Such an agent would fill a major vacuum in healthcare for men.
A third population of men undergo one of the traditional therapies in which case their recovery is assessed by monitoring the rate of change or the doubling time of their PSA levels which serve as an indicator of how rapidly their cancer is likely to return. An agent that is effective in reducing PSA levels and in moderating PSA doubling times could be used in combination with traditional therapies to help prevent the recurrence of prostate cancer thus significantly extending the life of this population of cancer patients.